Question

In a moleculte A - B, electronegativities of atom A and B are 2.0 and 4.0
respectively. Calculate the percent ionic character of A- B bond using (i) Pauling equation (ii) Hannay and
Smith equation.

Answer 1

(i) According to Pauling equation
% ionic character = `18 (chi _(A) - chi_(B))^(1-4) = 18 (4 - 2)^(1-4) = 18 xx 2 ^(1-4) = x (say)`
` long x = log 18 + 1.4 log 2 = 1.2553 + 1.4 xx 0.3010 = 1.6767`
x = Antilog 1 .` 6767 = 47. 50 %`
(ii) According to Smith and Hannay equation
` %` ionic character = `16 (chi _(A) - chi_(B)) + 3.5 (chi_(A) - chi_(B))^(2) = 16 xx 2 + 3.5 xx 2^(2)`
` = 32 + 14 = 46 %`